1. Field of the Invention
The present invention relates generally to machine elements that move relative to one another and to seals and bearing surfaces between such machine elements. More particularly, at least one of a sealing and a bearing function may be performed by way of a sleeve element according to the present invention.
2. State of the Art
Seals are conventionally used in maintaining a substance, such as a fluid or gas, located in one area or zone from communicating with another area or zone while allowing relative movement between two or more mechanical components. Typically, one of the mechanical components may traverse through both of the areas or zones. Such seals may also be used in keeping contaminants, such as dirt, dust, or other particulate-type materials, from becoming positioned in an area where one mechanical component moves relative to the surface of another mechanical component. Otherwise, repeated movement between the mechanical components, in combination with the presence of contaminants, may cause damage to the surfaces of the one or more mechanical components as well as to sealing elements.
One common example of mechanical components that move with respect to one another is a piston and bore. For instance, a piston may have an outer surface that is complementary and generally coaxial with the inner surface of a bore in which the piston moves axially, with or without rotation. It is usually desirable that no fluid flow communicate around the piston, so that pressure within the bore may cause the piston to move. Moreover it is also preferred that the piston remain relatively centered within the bore, to prevent the surfaces of the piston and the bore from contacting one another.
Accordingly, in conventional approaches, a piston may be often provided with a seal that prevents leakage, a separate bearing or guide to maintain the relative position of the piston within the bore, and a scraper to remove contaminants on the surface of the bore to inhibit damage to the piston, bore, or sealing elements. More specifically, a separate T-cap seal assembly and a separate wear guide or bearing element may be conventionally employed in piston designs. Also, as will be appreciated by those of ordinary skill in the art, the ability to maintain adequate lubrication between two relatively movable machine components, as well as the ability to limit contaminants from entering between the two relatively movable machine components, greatly enhances the working efficiency of the machine components and also greatly reduces wear of such components, to increase the usable life thereof.
Although the conventional configuration performs as intended, the conventional designs require numerous separate components to form a bearing surface and sealing element between relatively movable machine components. Therefore, in view of the shortcomings in the art, it would be advantageous to provide an improved seal configuration.